Improvement in elevators



MELANETHN HANFORD.

Improvement in Elevators.

Ptented March 26 MQW@ Mp@ MELANGTHON HANFORD, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN ELEVATQRS.

Specification forming part of Letters Patent No. 124,952, Vdated March 26, 1872.

to the accompanying drawing making part ofy this specification, and in which- Figure I is a plan, and Fig. 2 a vertical and longitudinal section of myinvention, while Fig. 3 is avertical section of the cylinders and drip-cup to be explained. Y

I have, in this invention, made provision whereby to distribute and equalize the draft or labor devolving upon twoor more hoisting ropes of an elevator-carriage, and incidentally to relieve the jar and thrusts resulting to the carriage under ordinary usage, and especially in the event of breakage of one or more of said ropes. My present invention consists in the employment, in combination with each rope ,or suspensory of an elevator-carriage where two or 4more ropes are employed, of a plunger traversing a well or cylinder, the lower. end of therope being attached to the plunger,

and a supply of oil being deposited within the f cylinder and over the plunger to interpose a henoncussion..` and thrusts,

triblim'iii In carrying into practice my invention, I obtain a pair of upright cylinders, A A, cast in one piece of metal and bolted in a secure manner to the central roof beam of the ele- Vater carriage.l Within each cylinder and standing ordinarily about midway thereof, I dispose a plunger, b, the rod c of which rises through the cap or head d of said cylinder, or a stuiiing-box, c, applied thereto to prevent escape of oil. Within each cylinder and over the plunger contained in it, I pour a sufficient quantity of oil or other proper oleaginous matter to till or about ll the space intervening between the top of the plunger and the capplate of the cylinder, a free communication being had between the two cylinders, as shown by the cross-passage f in the drawing, in order to insure an equilibrium of 'pressure upon the body of oil contained in them. The bottom of each cylinder is perforated with an orifice, g, which serves as an air-vent to relieve the vacuum which would otherwise exist below the plunger, and to permit of escape' of any minute quantity of oil which may escape between the plunger and cylinder. This latter contingency is a remote one, as the plunger tits or should fit so tightly within the cylinder as to render escape of oil impossible. A suitable drip-cup, H, is placed below the orifice g to arrest any oil which may escape by way of such orifice. It will be apparent that, by means of the cylinders A A and pistons or plunger b, in combination with the ropes, as explained, the dra-ft upon the rope is equalized and an equilibrium established which is productive of very benelicial results, while the oil or its equivalent serves as a cushion to relieve the carriage and ropes from the effects of any jerking or thrusts upon the latter.

The advantages of my improvement will be especially apparent on breaking of one of the ropes which actuate the carriage, as in this event the labor devolving upon the fractured rope is borne by and distributed equally and generally throughout the remaining ropes, and this distribution and disposition of labor is brought about gradually, owing to the length of time required for the oil to pass through the oil-passagef, which it must do as it is displaced by the release and fall of the plunger belonging to the fractured rope and the corresponding ascent of the other plun gers.

Although I have shown in the present instance one pair of ropes, cylinders, and plungers, it has been for the purpose of illustrating the nature and purposes of my invention. In practice I shall usually employ four ropes, and in some cases may adopt even more.

I claim- The cylinders a a and plungers b, as applied to an elevatorcarriage and connecting with the hoisting ropes thereof, such cylinders hav ing open communication eachwith the other at top, and the orifices g at bottom, and pro` vided wit-h a quantity of oil or its equivalent, the whole being for purposes stated.

MELANCTHON HANFORD. Witnesses:

FRED. CURTIS, WALno E. BOARDMAN. 

